const fp = require('lodash/fp')
// 数据
const cars = [
	{ name: 'Ferrari FF', horsepower: 660, dollar_value: 700000, in_stock: true },
	{ name: 'Spyker C12 Zagato', horsepower: 650, dollar_value: 648000, in_stock: false },
	{ name: 'Jaguar XKR-S', horsepower: 550, dollar_value: 132000, in_stock: false },
	{ name: 'Audi R8', horsepower: 525, dollar_value: 114200, in_stock: false },
	{ name: 'Aston Martin One-77', horsepower: 750, dollar_value: 1850000, in_stock: true },
	{ name: 'Pagani Huayra', horsepower: 700, dollar_value: 1300000, in_stock: false }
]

// 1.
let isLastInStock = fp.flowRight(fp.prop('in_stock'), fp.last)
// console.log(isLastInStock(cars))


// 2.
const firstCarName = fp.flowRight(fp.prop('name'), fp.first)
// console.log(firstCarName(cars))


// 3.
let _average = function (xs) {
	return fp.reduce(fp.add, 0, xs) / xs.length
} // <- 无须改动

let averageDollarValue = fp.flowRight(_average, fp.map(car => car.dollar_value))
// console.log(averageDollarValue(cars))


// 4.
let _underscore = fp.replace(/\W+/g, '_') // <-- 无须改动，并在sanitizeNames中使用它

const sanitizeNames = fp.map(fp.flowRight(_underscore, fp.toLower, fp.prop('name')))
// console.log(sanitizeNames(cars))

